Float switch



May 20, 1930. G. R, GERLACH ET AL FLOAT SWITCH Filed April 2, 1928 INVENTORS ATTORNEY Patented May 20, 1930 UNlTED STATES PATENT OFFICE GEORGE R. GERLACH AND HENRY R. ARENTON, OF SPOKANE, WASHINGTON FLOAT SWITCH Application filed April 2, 1928.

The object of this invention is to provide a novel means for signaling an alarm when depletion of the liquid contents of a tank reaches a predetermined set minimum.

The device of this invention, while not essentially limited thereto, is especially designed for use in connection with fuel oil storage supply tanks and the most prevalent use is in connection with tanls of this nature which are in private homes for supplying fuel oil to oil burners of furnaces.

The mechanism includes a normally `open circuit in which is interposed any suitable form of a signaling or alarm device, together with a circuit closer, and the invention involves a novel form of device for actuating the circuit closure and which device acts by gravity, responsive to a suflicient depletion of the liquid contents.

A further feature of the mechanism resides in a liquid filling and gravity acting circuit closing device which is normally submerged in the liquid and which is of such light weight construction that when said device is immersed, it is to all intents and purposes, in an equilibrum of pressure, or other words, practically self sustaining so that only the slightest supporting stress is necessary to maintain said device in position.

A further feature of the invention resides in novel means for shielding the circuit closing device from the violent agitation of the tanks contents while the contents thereof is being replenished.

A further feature of the invention consists in a novel structure combining the shielding feature and affording means whereby the tank can be filled through the same opening through which the actuating mechanism extends.

The invention has many other objects and features which will be more fully described in connection with the accompanying draw- 45 ing and which will be more particularly pointed out in and by the appended claims.

In the drawing Fig. 1, is a vertical sectional view of a fuel tank equipped with the preferred form of if@ the device cf this inventioni Serial No. 266,840.

Fig. 2, is an enlarged sectional view on line Q2 of Fig. 1.

Fig. 3, is a sectional view on line 3 5 of Fig. 2.

Fig. 4, is a fragmentary top plan view and partial diagrammatic view of the circuit.

Like characters of reference designate similar views throughout the different figures of the drawing.

A tank is shown having suitable bottom, side and top walls 1, 2 and 3, respectively, which may be of any form or size and which may be suitably located in practical communication with the oil burner of a furnace or any other receiving deposition. For mere purposes of illustration, we have shown a draw-off pipe at 4.

Said top wall 3 is conventionally shown as having a filling bung 5, that is exteriorly threaded. A fitting 6 is shown threaded on bung 5, and said fitting has a branch 7 into which the end 8, of a filling pipe 9, or section thereof, is threaded, and the pipe 9 is suitably provided with a cap 10. However, some tanks have special filling openings different from that shown. Y

In the novel fitting shown, the same is provided with a reducer or reduction branch 11 having a bore 12, the purpose of which will later appear. The web structure of said fitting is formed into an internally threaded nipple 13, that projects downwardly into the interior of the fitting, as shown, and when a connection is made with said nipple, as will be presently explained, the chamber 12, is divided off from the remainder of the interior of the fitting which I will designate at 141-, and which may be termed the filling channel.

The electrical port-ion of the mechanism will next be described in detail.

The top of the reducer is shown closed by a lid 15, which is preferably of insulating material such for instance as fiber, of disclike form. We have shown the same secured by means such as screws 16, to the fitting 6. This disc 15 closes the chamber 12, eX- cept for an aperture 17 preferably cent-rally disposed therein. A circuit closer is mounted on said disc 15 and the same may include W0 '22, out of' contact with terminals 18.

spring Contact terminals 18 anchored to disc 15 by the lower ends of rods 19 and nuts 20, wherein one of said rods is fully shown in Fig. 3. A contact yoke of substantially U- shaped form and of inverted disposition has a bight 21 and limbs 2Q, the lower ends of the latter being adapted to close circuit through terminals 18, as will be obvious from the drawing. Guides 23, suitably mounted in disc 15, serve to prevent rotation of vthe contact yoke irrespective of the position of the latter.

Ve will nextbriefly describe the diagrammatic electrical circuit for signaling depletion of the tanks contents.

The rods 19, actually function as binding posts and to lool? a. protecting cover, which is in the form of a cap 24e, that encloses a circuit closer. As shown in Fig. 3, said posts extend up through the top wall of said cap and provided with Vshoulders 25, between which and the cap a suitable insulation 26 may be interposed. A lire insulating disc 27, is disposed above the cap 2st and a nut 28 serves to rigidly hold the cap 2li in position. A nut 29, acts as a binding post nut, in the' usual manner. Thus, we can connect the leads 30 and 31, to the posts 19, as now clearly shown, outside the cap 2li. We have indicated a source of electric current at 32, and a lamp 33, both interposed in the circuit portion shown in F ig. 4.

lt will now be clear that the circuit will be open when the limbs 22 are out of contact with the terminals i8, as shown in 1 and 3. As the specific character of electrical means is not claimed, it is believed that the disclosure thereof herein made will be amply sufhcient to enable anyone skilled in the art to make and use the same.

A description will next be made of the means for actuating the circuit closer.

A supporting line, which in part is shown in the form of a rod or spindle 3e, has its upper end suitably and rigidly secured to the bight 21, of said circuit closer and said spindle 34 extends upwardly through said opening 17, in disc 1.5, with a free working clearance. An actuating spring surrounds said spindle 341-, and is interposed between an adjustable nut 36, and disc l5 and normally acts to elevate the yoke and its limbs A lower portion or section of the supporting line is shown in the form of a chain37, which will later be more fully described.

The invention involves a shield structure which as shown is in a tube section 38 and a cup section 39. Said tube section 38 is threaded into nipple 13 and a gland nut 40, is shown threaded into the upper end of tube 38. This gland nut 40, has a bore that affords passage of spindle 34 and permits the latter 'to freely slide therein. Said nut lO and disc 15, close chamber 12, and in order to prevent any danger of sparks reaching the contents of the tank, we pack the chamber 12, and in practice, we preferably use a grease that also serves to lubricate the spindle and facilitate sliding movement of the latter through nut l0 and disc 15. This packing, of whatever nature, complies with regulations for safety even when the tank contains liquid fuel. A small air vent 41, is disposed in tube 38, not only at a high point therein but on that peripheral side remote from the path of the incoming liquid, as indicated by the arrow.

lt will now be clear that the tube 38 is secured in the fitting 6, which is also a filling channel, and depends therefrom down into the tank and thereby protects and shields the chain 37, from interference by the violent agitation caused by filling the tank, and allows said chain to work freely.

Said cup section 39, is slightly enlarged in diameter with respect to the tube 38 and may be connected at its upper end in full communication with the lower end of said tube, as shown. Said section 39, is preferably cylindrical in cross section and has an open bottoni 42, in full communication with the contents of the tank and may also have one or more openings 43. Thus, at any rate, the liquid level in the shield structure will always be the same in the tank, and section 39 is disposed the bottom 1, of said tank.

ln section 39, is disposed what will be termed an actuator which, in the present case is in the form of a cup la having` imperforate bottom and cylindrical Walls and an open top. A slight rod 45, or the like, may be provided for connection with the lower end of chain 37, as shown. lVhile the cup 44, is slidable in section 39, there is only a slight working clearance, and the cup is relatively elongated and has a considerable capacity. Further, it is a feature to make this actuating cup of very light weight material so that its weight will be reduced to a minimum. Thus, when the level in the tank is above the cup 44C, and the latter is submerged, the cup will almost be in an equilibrium of pressure and hence the spring 35, may be very light because the load is so light that it carries.

Describing the operation of our invention, it will be clear that when the level Vis at A, or at any point above the cup 44, the latter will not only be full of liquid, but will be submerged in liquid eXteriorily as well. The spring 35, will support the cup 44e, which need not weigh more than a few ounces even including the supporting line comprising sections 34 and 37. The circuit will be open, as indicated in F ig. 1.

scends so that buoyancy of the cup will fail to support the latter, say at level B, or before this has been reached, the weight of the contents of cup lll will quickly overcome spring 35, and as the limbs 22 only have a fraction of an inch to travel before contacting with ter- Now as the level deminals 18, the circuit will be quickly closed, and maintained closed, as long as the level is thus depleted. rlhis will cause the lamp 38, to glow, or energize any suitable signal or alarm to indicate that the level of the tank has desee ded to such an extent that the tanl should be re-iilled.

As the tanl; is being re-iiiled, and the liquid level ascends above the cup t, the Weight of the latter will be reduced to the actual weight oit the cup and the .supporting line, and consequently, the spring 235 M. be adequate to restore the parts to the position shown in Fig. l.

It will now be clear that by having an .ctuating cup of relatively large capacity, even though it is oil minimum weight,

very quickly aufL positively operate the circuit loser by a gravit-y acting device which is devoid of springs except for restoration purposes, which is an ideal 'fi-notion or springs.

It is believed that the device ci invention will be i'ully understood from the foregoing description, and while we have hereje shown and described one specific form our invention, we do not wish to be thereto except for such limitations claims may imp rt.

lWe claim:

l. In a device for signaling liquid in supply storage, a tanl contain a supply or' liquid and lr draw-oil pipe and an upper iilin shield tube secured in and dependi said iitting into said tank being s tially out oi communication with the en liquid passing through said fitting, .Y shield near the bottom oi said tanli and open at its lower end to the contents thereof and having its upper end secured in open conn niunication with the lower end oi said tube whereby the liquid level in said i'ianh and shield tube and cup shield will always be the same, a light weight signal actuating cup freely slidable in said cup shield having an open top and adapted to contain a quan tity of liquid to lower said cup when the level in said tank descends below the top of said cup7 a. circuit closing` device in said fitting adapted to energize an alarm, a supporting line connected with said circuit closing device and with said cup, and a spring normally holding said circuit closing device in a circuit open posit-ion and supporting said cup in a predetermined positionl when said cup is immersed.

2. ln a device for signaling depletion oi'" liquid in supply storage, a tank adapted to contain a supply of liquid and having a fitting thereon, a shield tube of relatively reduced diameter secured to and dependingl rom said iitting downv-Jardly into tanlt, a cup shield of relatively enlarged diameter near the bottom of said tank and open thereto and being detachably connected in open communication with said tube shield, a light weight signal actuating cup having an open top freely slidable in said cup shield and normaily immersed and filled with liquid thereby being devoid or" buoyancy, a circuit closing device on said iitting adapted to energize an alarm, a flexible supporting line connected with said circuit closing device and said cup, and a light tensioned spring normally 'ng said circuit closing device in a circuit position and acting through said device to support said cup in a predetermined position in said cup shield when said cup is imA iersed.

3. In a device for signaling depletion of liquid in supply storage, a tank adapted to certain a supply et liquid and having a tillitting structure provided with a filling icl, a laterally extending filling pipe dei ng to channel, a. tubular shield ted in said iitting structure and extend e' downwardly through said iilling channel said tank and being substantially out of aJ 'on with the liquid passing channel and being open to said Ay open cirlevice having a minimum of in a circuit open to a circuit ition, a weighted actuator in said *ar shield pendently connected with said to close circuit therethrough and said atei' being normally in an equilibrium pressure until the liquid level has deecenu o. to a predetermined point, and being after adapted to move said device into and retain it in a circuit closing position.

ln witness that We claim the foregoing as our own, we hereby aflix our signatures.

GEORGE R. GERLACH. HENRY R. ABENTGN.

lia

liG 

